compositions



Patented May 6, 1930 UNITED STATES Hammer PATENT OFFICE GEORGE B. PEEBLES, OF NEWARK, NEW JERSEY HEAT-INSULATING MATERIAL No Drawing.

This invention relates to heat insulating other shapes and employed as a structural material or as a sheathing.

The material is particularly adapted for use as wall board to replace fiber and plaster boards and has several advantages which make it superior to the latter materials. It is fire-proof and non-heat conducting, and it does not disintegrate when subjected to high temperatures. It is, moreover, tough and elastic and does not chip or crack.

Owing to its low heat conductivity the material is admirably adapted for use as an insulator for heat radiating or absorbing surfaces. It can be molded easily into any desired form for example to afford a covering for pipes or conduits through which hot or cold fluids are conducted.

Another advantage of the invention is that it affords a use for waste products which have long been regarded as useless and a nuisance. Large quantities of such products have accumulated and can be utilized together with the waste products which are discharged daily from large chemical plants.

The waste roducts referred to are those resultlng from the manufacture of alkalis caustic soda (sodium hydroxide) and consist principally of mixtures of calcium comounds to 'ether w1t com oun s 0 so ium ma nes1um. iron a ummum uc pro uc s are pro uce 1n large quantities and thousands of tons thereof have been deposited in dumps. In fact, the disposition of this waste is a serious problem.

The composition of the products varies somewhat with the source and it is modified on exposure to the weather by the leaching of soluble compounds such as calcium chloride and sodium chloride therefrom. ,The Waste product from the manufacture of soda ash by the ammonia-soda process consists Application filed August 8, 1928. Serial No. 298,413.

principally of calcium oxide andor hydrox- 1nater1al and articularly to a composition 1de. calcium car onate ca 0mm c on e an which may be ormed or molded in sheets and soc mm c on e W1- ot sillca. 1ron and aluminum oxides. magnesium oxide and calc1um su some or m varymg proportions or ischarged partly in suspension and partly in solution.

If weathered the ro ortion of soluble c nstituents 1s lower and that of calcium Ey- 1he waste fire resisting material suitable for many purposes as hereinbefore indicated. To accomplish the purpose of the invention, the waste material is first dried. If fresh pro uc s are treated, evaporation may be necessary. The drying is completed at a temperature such 7" as to remove all moisture and substantially all water of crystallization. The product is crushed and ulverized and is then mixed 5 with suitable proportions of silicate of soda 30 such as soda ash (sodium carbonate) and and ma nesium oxide. It is termed mto die desired shape eltfier as a sheet or otherwise an 1s su ec ed to a very considerable ressure wh1ch serves to consolidate the materlal.

SlllCOIl. Sheets or other forms may be reinforced with any suitable material such as paper, for exshipped as desired, and it may be used as as ordinary wall board or for special uses where heat insulation is required. Fibre; x

such as asbestos may be mixed with the com; position e ore 1 is subjected to pressure.

As an example of the invention, a waste product having substantially the following with the addition of magnesium oxide and composition: silicate of soda.

Per cent In testimony whereof I afiix my signa- Silica (SiO 5.84 turb- 5 Iron and aluminum oxides (Fe O and GEORGE S- 7 A1 0 3.50 Calcium oxide (CaO) 5.17 Calcium hydroxide (Ca(OH) 13.42 Magnesium oxide (MgO) 4.52 10 Calcium carbonate (CaCO 22.17 7

Calcium sulphate (CaSO 395 Calcium chloride (CaCl 21.79 Sodium chloride (NaCl) 19.06 g Moisture at 110 C .52 1 80 Total 99.94

may be mixed after heating to remove moisture and water of crystallization in the proportion of 100 parts of the waste roduct with 20 10 parts of ma nesium ox1de and 5 parts of 85 silicate of so a. e mix ure after thorough We intimate mixture is formed in the desired shape. It may be spread in 5 an even layer to form a sheet and then subjected to a ressure of 000 ounds er square inch. Ifie consolidated sheet may ming layers of paper at the faces thereof or embedded therein.

Suitable moulds may be used to form other shapes, and such shapes may be produced i similarly by the application of pressure to the composition.

No exact explanation of the effect of the magnesium oxide and silicate of soda upon the com osition can be presented. The mechanism o the reactions, if such reactions occur, is unknown. Nevertheless it is apparent that the characteristics of the composition are modified with respect to cohesion and hardness by such additions and that the result is a material having new properties which make it suitable for uses to which the waste product is not adapted.

It will be understood that the composition as described is illustrative of the invention. The waste product may vary in respect to the ingredients and proportions thereof and the proportions of added materials may likewise vary. Other changes may be made in compositions and procedure without departing from the invention or sacrificing any of the advantages.

As the waste products from the manufacture of soda ash by the ammonia-soda process 120 are discharged or precipitated partly in suspension and partly in solution, the term precipitated as hereinafter used in the claim is 1 not necessarily limited to a chemical precipitation with a reagent. 125

I claim:

A lire-resisting and heat-insulating composition comprising the precipitated waste products from the manufacture of sodium compounds by the ammonia-soda process, 130 

